摘要
我国陆相侏罗系—白垩系界线长期存在争议。最近黑龙江东部海相化石的检验使这一问题有所突破;根据与海相层交互的陆相层中各门类化石的对比,又使其它地区(包括浙闽赣地区)的问题也开始解决。众所周知,浙闽赣地区侏罗系—白垩系界线就在建德群(或其相当地层)之中或其顶、底。本文依据与黑龙江东部的对比,并据本区近年来采用多种方法测得的,一批可靠性大的同位素年龄资料,提出了侏罗系—白垩系界线的新认识。
It has been in dispute for a long time whether the Jiande Group and its related strata in Zhe-jiang, Fujian and Jiangxi Provinces, southeastern China, should be assigned to the Upper Juras-sic or Late Cretaceous. Such disputes also exist concerning the continental Jurassic-Cretaceous boundary in different parts of China. Recently, studies of marine fossils in eastern Heilongjiang have resulted in some breakthroughs in the problem. In 1970's, the Jurassic-Cretaceous bound-ary in eastern Heilongjiang was placed at the top boundary of the Jixi Group and Longzhaogou Group in the Stratigraphical Table of Heilongjiang Province. However, at present, fossils in ma-rine interbeds have revealed that the major beds containing coal in the two groups mentioned above basically belong to the Lower Cretaceous System. Correlation between eastern Heilongjiang and its related parts of China shows that the upper part of the Rehe Group, western Liaoning, and the upper part of the Jiande Group, western Zhejiang Province, should belong to the Lower Cretaceous System rather than the Upper Jurassic System.Now that the Shouchang Formation in the upper part of the Jiande Group belongs to the Lower Cretaceous, where should the Jurassic-Cretaceous boundary be set? Owing to shortage of fossils in the Huangjian Formation and Laocun Formation below the Shouchang Formation, western Zhejiang, it is difficult to solve the problem by the biostratigraphical method. Fortunate-ly, correlation carried out through many advanced methods by different institutions and a lot of reliable isotopic age data obtained in these areas make it possible to solve the problem. Based on the data from some representative areas in the three provinces, this paper reveals that the Jiande Group and its related strata mainly belong to the Lower Cretaceous, and only in the west part of the region, do some strata belong to the Upper Jurassic.
出处
《地质论评》
CAS
CSCD
北大核心
1997年第1期25-32,共8页
Geological Review
关键词
侏罗系
白垩系
界线
浙闽赣地区
地层
Jurassic, Cretaceous, boundary, Zhejiang-Fujian-Jiangxi region
